The winter wheat line TP 114 derived from CI 12633, a Triticum timopheevi derivative, has two unlinked dominant genes conditioning resistance to the powdery mildew fungus (Erysiphe graminis f. sp. tritici). One of the genes is identical to gene Pm2 (Ml u ). The other gene differs from the eleven Pm and/or Ml designated genes; a temporary designation, Ml f ,is proposed for this gene. Gene Ml f is closely associated with a gene conditioning resistance to the stem rust fungus (Puccinia graminis f. sp. tritici), probably gene Sr9c. The winter wheat line TP 229 derived from Triticum carthlicum has one dominant mildew resistance gene identical to gene Ml e in Weihenstephaner M 1.